132 



REPORTS ON INVESTIGATIONS AND PROJECTS. 



While the few observations here recorded show the rate of growth of dif- 

 ferent individuals to be quite irregular, they nevertheless indicate in a gen- 

 eral way that the percentage of increase in size becomes progressively smaller 

 from year to year. 



In the following table are presented records for a number of specimens of 

 the same forms which were put upon tiles in July 191 1. These results con- 

 firm those obtained from the previous observations and are in some instances, 

 because of the smaller sizes of the specimens taken for observation, much 

 more striking than were those previously obtained. 



Tile and species. 



Tiio T / '^^ flabellum... 



•^"^' t P- flexuosa 



Til/. 1 / P- flexuosa (a) 

 ^''^ ^ t P. flexuosa (b) 

 Tile 3. G. flabellum .. 



Increase. 



p. ct. 



127.69 

 15-38 

 20.62 



71-43 

 202.43 



Upon the surface of the coral head, where are growing specimens recorded 

 in the first table given above, there were found on August 21 of this year, 7 

 specimens of P. flexuosa, which had become attached since July 23, 1911. 

 The lengths of these specimens were in order of magnitude, 25 mm., 26 mm., 

 31 mm., 32 mm., 42 mm., 42 mm., and 46 mm., respectively. On a shallow 

 reef east of Loggerhead Key, where observations and measurements of the 

 gorgonians have been made for the past two years, there were found 15 

 specimens of P. Hexuosa less than 50 mm. in length. These also were not 

 present, or, at least, not large enough to be recognized in July 1911. 



Observations made in June and July of 1910 and 1911 showed that all 

 female specimens of P. flexuosa examined contained ripe eggs and that they 

 could be caused to segment by the ordinary methods of inducing artificial 

 parthenogensis, while all specimens examined this season after August 15 

 had given off their sexual products. On the basis of these observations it 

 seems certain that these small specimens are practically one year old. The 

 fact that they are all of nearly the same size would indicate also that the 

 breeding season is of comparatively short duration. 



Upon the above-mentioned reef, east of Loggerhead Key, there were 

 found also 26 specimens of G. flabellum less than 65 mm. in height, which 

 were not recognizable when all of the specimens upon that reef were meas- 

 ured in July 191 1. As these specimens are approximately one year old, the 

 records of the specimens put out upon tiles in July 1911 makes it possible to 

 carry the growth record for this species to the end of the second year. 



